Tissue excision device with an independent needle

ABSTRACT

A biopsy device includes a coring cannula, a retract stylet, and a localization needle. The coring cannula has a longitudinal axis and a shaft centered on the axis. The stylet has a tip containing at least one blade and a central passage. The localization needle has a channel and is slidably disposed within the central passage. A drive mechanism rotates the cannula and moves the cannula in a direction parallel to the longitudinal axis of the cannula. A guide element has a first end and a second end and is slidably disposed within the channel of the localization needle. The guide element is movable from a first position to a second position within the localization needle.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication Ser. Nos. 61/319,159; 61/319,160; 61/319,162; 61/319,155;61/319,148; 61/319,157; 61/319,209; 61/319,210; 61/319,217; 61/319,218;61/319,223; 61/319,528 and 61/324,172, filed Mar. 30, 2010; Mar. 30,2010; Mar. 30, 2010; Mar. 30, 2010; Mar. 30, 2010; Mar. 30, 2010; Mar.30, 2010; Mar. 30, 2010; Mar. 30, 2010; Mar. 30, 2010; Mar. 30, 2010;Mar. 31, 2010 and Apr. 14, 2010, respectively, all of which are herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to surgical instruments, andmore particularly, to a device for percutaneous excision of tissue,percutaneous excisional breast biopsy or percutaneous incisional breastbiopsy.

BACKGROUND OF THE INVENTION

Generally, to date there have been two coring type, excisional breastbiopsy devices developed and marketed. These devices are described inthe following U.S. Pat. Nos. 5,111,828; 5,197,484; 5,353,804; 6,080,113;6,267,732; 6,383,145; 6,551,253; 5,782,775; 5,817,034; 5,857,982;6,036,657; 6,077,231; 6,165,137; and 6,213,957, all of which are herebyincorporated by reference.

These devices were originally developed for use with stereotacticimaging equipment. Generally, these devices use the same basictechnology. The device disclosed in the '253 patent is exemplary. Thebiopsy device includes a localization needle with a guide wire preloadedinto the device. The localization needle and guide wire are used tolocate and localize the target area. The methodology of their usage canbe summarized as follows:

1. Localize the target area with needle/wire hook;2. Translate device up to the target area using a bladed stylet;3. Core out the target specimen using a bladed cannula; and4. Transect the tissue using a garrote wire to release the specimen.

The device can either by a handheld device or may be a fixed device. Thebelow more detailed description of the method of using a prior artdevice is described with respect to a handheld device.

First, a localization needle is placed at the center of the targettissue. A localization wire is used to fix the handheld device to thetissue. After the localization wire is deployed, a stylet is manuallyadvanced to a point just proximal of the target.

One problem associated with the current device is that the localizationhook has very little holding power.

Another issue related to the prior art devices is the potential of thestylet to push and/or compress, i.e., the tissue in front of the stylet,i.e., “snowplow”.

After the stylet reaches the target tissue, the cannula is manuallyadvanced over the target tissue. With the cannula advanced over thetarget tissue, a mechanism, such as a garrote wire is activated to severthe target tissue from the breast. With the target tissue severed fromthe breast, the device, along with the target tissue with the cannula,may be removed.

Generally, these prior art devices are purely mechanical devices, i.e.,in other words, the coring cannula is advanced by hand. The surgeon oruser rotates a knob that activates a gear system to rotate and advancesthe coring cannula. This results in a relatively slow, intermittentadvance of the cannula due to the start/stop motion of the surgeon. Thestart/stop motion can increase patient discomfort, as well as produce anundesirable irregular specimen shape.

As discussed above, once the cannula has been advanced over the targettissue, a garrote wire may be used to cut the sample tissue (which isinside the cannula) from the breast so that it may be removed. Thegarrote wire has several limitations. Typically, the garrote wiretraverse (at least partially) along the length of the device, then isbent at a 90 degree angle, after which it encircles an inner surface ofthe coring cannula. The right angle in the garrote wire results inrequiring a large amount of force to pull on the garrote wire totransect the tissue sample. Additionally, the garrote wire is generallylocated a distance behind the cutting edge of the coring cannula. Thisresults in a core of tissue which is cored by the coring cannula, whichis not transected by the garrote wire, and thus remains in the breast.Furthermore, the garrote wire may tear the tissue rather than cuttingthe tissue. Additionally, dense tissue can be pushed aside rather thancut.

Another issue related to prior art designs is the size of the cuttingedge of the cannula with respect to the stylet. Prior to entry of thedevice into the breast, a skin incision is made using a scalpel. Thisincision is generally just slightly wider than the diameter of thecannula. Once the incision is made, the stylet is advanced in thebreast, up to the point where the coring blade is ready to enter theincision. At this point, the surgeon will use nerve hooks to grab theskin and open the incision to allow the cutting edge of the cannula toenter the breast. However, the process of using the nerve hooks to grabthe skin to make the incision wider can be cumbersome and inefficientand can cause patient discomfort.

The current devices use a stylet with integral cutting blades. The flatstylet blades are fixed to the stylet which may result in severaladverse conditions. First, the close proximity of the cutting edge ofthe stylet blades to the ramp or stylet tip results in the pushing orcompression or other inadvertent movement of the tissue by the stylet.The prior designs also results in a fixed minimal proximal margin equalto the length of the stylet system.

The present invention is aimed at one or more of the problems identifiedabove.

SUMMARY OF THE INVENTION

In a first aspect of the present invention, a needle assembly isprovided. The needle assembly includes a localization needle, a handle,a guide element and a plunger. The localization needle has first andsecond ends and an internal bore. The handle has first and second endsand an internal bore. The first end of the needle is fixed to the secondend of the handle. The internal bore of the needle and the internal boreof the handle form an assembly bore therethrough. The guide element hasa guide rod and a locking member. The guide element has first and secondends and is removably contained within the assembly bore. The lockingmember is fixed to the second end of the guide rod. The plunger includesa pushrod and an actuation element coupled to the pushrod. The plungeris movable from a first state to a second state. One end of the pushrodacts on the first end of the guide rod, forcing the locking member outof the needle as the pushrod is moved from the first state to the secondstate.

In a second aspect of the present invention, a biopsy device isprovided. The biopsy device includes a housing, a coring cannula, astylet, a localization needle, a motor assembly, a variable speedcircuit electrically coupled to the motor assembly, a forward/reverseswitch, and a speed control switch. The coring cannula is coupled to thehousing. The stylet has a tip containing at least one blade and acentral passage. The localization needle has a channel and is slidablydisposed within the central passage. The motor assembly is coupled tothe coring cannula for controllably rotating the cannula. Theforward/reverse switch is electrically coupled to the variable speedcircuit for controlling the direction of movement of the cannula. Thespeed control trigger is electrically coupled to the variable speedcircuit for responsively controlling the speed and rotation of thecannula as a function of the forward/reverse switch and actuation of thespeed control trigger. The needle assembly includes a localizationneedle, a handle, a guide element and a plunger. The localization needlehas first and second ends and an internal bore. The handle has first andsecond ends and an internal bore. The first end of the needle is fixedto the second end of the handle. The internal bore of the needle and theinternal bore of the handle form an assembly bore therethrough. Theguide element has a guide rod and a locking member. The guide elementhas first and second ends and is removably contained within the assemblybore. The locking member is fixed to the second end of the guide rod.The plunger includes a pushrod and an actuation element coupled to thepushrod. The plunger is movable from a first state to a second state.One end of the pushrod acts on the first end of the guide rod, forcingthe locking member out of the needle as the pushrod is moved from thefirst state to the second state.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a drawing of a biopsy device with an integrated needle,according to an embodiment of the present invention;

FIG. 2 includes a series of views of the biopsy device of FIG. 1illustrating operation thereof;

FIG. 3 is an isometric drawing of a biopsy device with an independentneedle assembly, according to an alternative embodiment of the presentinvention;

FIG. 4A is a drawing of the independent needle assembly of FIG. 3;

FIG. 4B is another drawing of the independent needle assembly of FIG. 3;

FIG. 5A is a drawing of a guide element of the independent needleassembly of FIGS. 3 and 4;

FIG. 5B is a larger view of a portion of FIG. 5A;

FIG. 6 is a isometric illustration of a handheld breast biopsy devicehaving a housing and a handle, according to an embodiment of the presentinvention;

FIG. 7 is a cut-away view of the handle of a breast biopsy device,according to an embodiment of the present invention;

FIG. 8 is a first cut-away view of a breast biopsy device illustratingthe drivetrain components, according to an embodiment of the presentinvention;

FIG. 9 is a second cut-away view of the breast biopsy device of FIG. 8;

FIG. 10 is a drawing of the housing, according to an embodiment of thepresent invention;

FIG. 11 is a drawing of the stylet, according to an embodiment of thepresent invention;

FIG. 12 a drawing of the cannula, according to an embodiment of thepresent invention;

FIG. 13A is an illustration of a guide element of an independent needleassembly, according to a first embodiment of the present invention;

FIG. 13B is an illustration of a partial view of the independent needleassembly of FIG. 13A, in the unlocking configuration;

FIG. 13C is an illustration of a partial view of the independent needleassembly of FIG. 13A, in the locking configuration;

FIG. 14 is an illustration of a guide element according to a secondembodiment of the present invention, in the unlocking configuration;

FIG. 15 is an illustration of the guide element of FIG. 14A in thelocking configuration;

FIG. 16A is an illustration of a guide element according to a fourthembodiment of the present invention;

FIG. 16B is a front view of the guide element of FIG. 16A in theunlocking configuration;

FIG. 16C is a side view of the guide element of FIG. 16A in theunlocking configuration;

FIG. 16D is a side view of the guide element of FIG. 16A in the lockingconfiguration;

FIG. 17 is a side view of a guide element according to a fifthembodiment of the present invention;

FIG. 18 is a side view of a guide element according to a sixthembodiment of the present invention;

FIG. 19A is an illustration of a partial view of an integrated needleassembly with a guide element in the unlocking configuration, accordingto an embodiment of the present invention;

FIG. 19B is an illustration of the integrated needle assembly of FIG.19A with the guide element in the locking configuration;

FIG. 19C is an illustration of the integrated needle assembly of FIG.19A with two three wires of the guide element retracted into thelocalization needle;

FIG. 19D is an illustration of a part of the guide element with a singlewire which remains in the target tissue to provide orientation of thesample;

FIG. 20A is a partial side view of a coring cannula in an initialposition and a final position, according to an embodiment of the presentinvention;

FIG. 20B is a front view of the coring cannula of FIG. 20A;

FIG. 21A is a partial side view of the coring cannula of FIG. 20B duringinitial advanced of a flexible transection blade;

FIG. 21B is a front view of the coring cannula and flexible transectionblade of FIG. 21A;

FIG. 22A is a partial side view of the coring cannula and flexibletransection blade in a second blade position;

FIG. 22B is a front view of the coring cannula flexible transectionblade in the second blade position;

FIG. 23A is a view of the flexible transection blade in an initialconfiguration, according to an embodiment of the present invention;

FIG. 23B is a top view of the flexible transection blade in a cuttingconfiguration, according to an embodiment of the present invention;

FIG. 23C is a front view of the flexible transection blade in thecutting configuration showing a cutting edge, according to an embodimentof the present invention;

FIG. 24 is a graphical representation of the drivetrain of the deviceand the flexible transaction blade in the initial position, according toa first embodiment of the present invention;

FIG. 25A is a graphical representation of the drivetrain of the deviceand the flexible transaction blade, of FIG. 24, in the final position;

FIG. 25B is a front view of the graphical representation of thedrivetrain of the device and the flexible transaction blade, of FIG. 24,in the final position;

FIG. 26 is a graphical representation of the drivetrain of the deviceand the flexible transaction blade in the initial position, according toa second embodiment of the present invention;

FIG. 27 is a graphical representation of the drivetrain of the deviceand the flexible transaction blade, of FIG. 24, in the final position;

FIG. 28A is a first cut away view of the graphical representation of thedrivetrain of the device and the flexible transaction blade, of FIG. 24,in the final position;

FIG. 28B is a second cut away view of the graphical representation ofthe drivetrain of the device and the flexible transaction blade, of FIG.24, in the final position;

FIG. 29 is a graphical representation of an alternative drivetrain,according to an embodiment of the present invention;

FIG. 30 is a graphical representation of a second alternative drivetrainin an initial position, according to an embodiment of the presentinvention;

FIG. 31 is a graphical representation of the second alternativedrivetrain in a final position;

FIG. 32A is a graphical representation of a flexible transection bladeand a coring cannula with a circular cutting ring, according to anembodiment of the present invention;

FIG. 32B is a front view of the flexible transection blade and coringcannula of FIG. 32A;

FIG. 33A is a graphical representation of a flexible transection bladeand a coring cannula with a partial cutting ring, according to anembodiment of the present invention;

FIG. 33B is a front view of the flexible transection blade and coringcannula of FIG. 33A;

FIG. 34A is a graphical representation of a flexible transection bladewhich forms the cutting edge of the coring cannula, according to anembodiment of the present invention;

FIG. 34B is a front view of the flexible transection blade and coringcannula of FIG. 34A;

FIG. 35 is a graphical representation of a prior art coring cannula withan internal cutting ring;

FIG. 36A is a graphical representation of a coring cannula with anangled cutting ring, according to an embodiment of the presentinvention;

FIG. 36B is a front view of the coring cannula and cutting ring of FIG.36A;

FIG. 37A is a first view of a garrote wire for use with the cutting ringof FIGS. 36A and 36B;

FIG. 37B is a second view of a garrote wire for use with the cuttingring of FIGS. 36A and 36B;

FIG. 37C is a third view of a garrote wire for use with the cutting ringof FIGS. 36A and 36B;

FIG. 38A is a graphical representation of a coring cannula with anexternal cutting ring, according to an embodiment of the presentinvention;

FIG. 38B is a view of a portion of the coring cannula and externalcutting ring of FIG. 38A;

FIG. 39 is a graphical representation of a coring cannula with anexternal cutting ring, according to an other embodiment of the presentinvention;

FIG. 40 is a graphical representation of a prior art coring cannula witha cutting ring;

FIG. 41 is a graphical representation of a coring cannula with a cuttingring, according to an embodiment of the present invention;

FIG. 42A is a side view of a prior art coring cannula and stylet;

FIG. 42B is a front view of the prior art coring cannula and stylet ofFIG. 42A;

FIG. 43A is a side view of a coring cannula and a collapsible stylet inan initial configuration, according to an embodiment of the presentinvention;

FIG. 43B is a first front view of the coring cannula and stylet of FIG.43A;

FIG. 43C is a side view of the coring cannula and stylet of FIG. 43A ina contracted configuration;

FIG. 43D is a second front view of the coring cannula and stylet of FIG.43A with the stylet in the contracted configuration;

FIG. 44 is a view of a prior art stylet;

FIG. 45 is a view of a stylet including an independent stylet mechanism,according to an embodiment of the present invention;

FIG. 46A is a first view of an expanding localization needle, accordingto an embodiment of the present invention;

FIG. 46B is a second view of the expanding localization needle of FIG.46A;

FIG. 46C is a view of the expanding localization needle of FIG. 46A withan actuation mechanism, according to a first embodiment of the presentinvention;

FIG. 46D is a view of the expanding localization needle of FIG. 46A withan actuation mechanism, according to a second embodiment of the presentinvention;

FIG. 47A is a first view of an expanding localization needle, accordingto an other embodiment of the present invention;

FIG. 47B is a partial view of the expanding localization needle of FIG.47A;

FIG. 48A is a first view of a stylet with a rotating blade, according toan embodiment of the present invention;

FIG. 48B is a second view of the stylet with the rotating blade of FIG.48A;

FIG. 49 is an illustration of a stylet with multiple rotating blades,according to an embodiment of the present invention;

FIG. 50A is a graphical representation of a portion of a breast biopsydevice with a garrote wire and a trigger mechanism includes a pair ofcleats;

FIG. 50B is a second graphical representation of the breast biopsydevice of FIG. 5A;

FIG. 50C is a third graphical representation of the breast biopsy deviceof FIG. 50A;

FIG. 50D is a fourth graphical representation of the breast biopsydevice of FIG. 50A;

FIG. 51A is a graphical representation of another embodiment of thetrigger mechanism of FIG. 50A;

FIG. 51B is a graphical representation of a further embodiment of thetrigger mechanism of FIG. 50A;

FIG. 52A is a top view of a graphical representation of a top view of abreast biopsy device having a rotatable trigger, according to anembodiment of the present invention;

FIG. 52B is a side view of the breast biopsy device of FIG. 52A;

FIG. 52C is a second view of the breast biopsy device of FIG. 52A; and

FIG. 52D is a third view of the breast biopsy device of FIG. 52A.

DETAILED DESCRIPTION OF INVENTION

Referring to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, the present inventionprovides a breast biopsy device 10 and a method of operating the breastbiopsy device 10.

With reference to FIG. 1, in one aspect of the present invention, thebreast biopsy device 10 is embodied in a handheld device 12. It shouldbe noted that the present invention may be embodied in a fixed device(not shown).

The handheld device 12 may include a housing 14 (see FIG. 10) and ahandle 16. In one aspect, the housing 14 is removable from the handle16. The handle 16 is reusable. The housing 14 (and all parts containedtherein) are disposable and generally provided sterile. In one aspect ofthe present invention, the device 10 may include an integrated needleassembly 18 (described below). In another aspect of the presentinvention, the device 10 may include an independent needle assembly 18′(described below).

With particular reference to FIGS. 10, 11 and 12, the housing 14 mayinclude an inner passage 22 (see FIG. 10). A coring cannula 20 isslidably mounted within the inner passage 22 of the housing 14. Thecoring cannula 20 has a longitudinal axis 24 and may include a shaft 26centered on the axis 24.

In one embodiment, the coring cannula 20 is coupled to the housing suchthat rotational movement of the coring cannula 20 about the axis 24results in linear movement of the coring cannula 20 along the axis 24.As discussed more fully below, the coring cannula 20 has a cutting edgeallowing it to cut through tissue as it is rotated and advanced.

It should be noted that in other embodiments, the coring cannula 20 maysimply rotate within the housing 14. Linear movement of the coringcannula 20 (to advance the device 10 and the coring cannula 20 into thebreast) may be provided by external mechanical means or by the user.

The breast biopsy device 10 includes a stylet 28, which includes astylet housing 38. With particular reference to FIG. 11, the styletincludes a tip 30. The tip 30 includes at least one blade 32 and acentral passage 34. The tip 30 may also include a slot 31 for the atleast one blade 32.

In one embodiment of the present invention, the stylet 28 is mountedwithin the coring cannula 20. The stylet 28 includes first and secondblades 32A, 32B integrated between two half portions 38A, 38B of astylet housing 38. The stylet 28 transects, dilates, and separatestissue as the device 10 is inserted or advanced towards the biopsy site.

A drive assembly 40 mounted within the housing 14 and the handle 16 (seeFIGS. 7 and 9) rotates the cannula 20 and controllably rotates thecannula 20. In one embodiment, the drive assembly 40 also moves thecannula 20 in a direction parallel to (and along) the axis 24. In oneaspect, the coring cannula 20 has a predetermined linear advancement perrevolution of the coring cannula 20. In one embodiment, thepredetermined linear advancement is 0.50 inches per revolution. In another embodiment, the predetermined linear advancement is 0.84 inchesper revolution.

The drive assembly 40 may include a motor assembly comprised of a DCmotor and step down transmission 42 and a drivetrain 44. The DC motorand step down transmission 42 is coupled to the drivetrain 44 (FIG. 9).The drive assembly 40 and the drivetrain 44 are explained more fullybelow.

In one aspect of the present invention, the drive assembly 40 rotatesthe coring cannula 20 as a single speed, for example, at or around 80revolutions per minute. Alternatively, the drive assembly 40 rotates thecoring cannula 20 at a variable speed (see below).

The needle assembly 18, 18′ may include a localization needle 54. Thelocalization needle 54 has an inner channel 56 and is slidably removablefrom the central passage of the stylet 28. The needle assembly 18, 18′further includes a guide element 52 (see FIGS. 4 and 5A). The guideelement 52 is used to secure the tissue while the coring cannula 20 isadvanced.

In one embodiment of the present invention, the guide element 52 has afirst end 58 and a second end 60. The first end 58 of the guide element52 is slidably disposed within the channel 56 of the localization needle54.

In one embodiment, the guide element 52 is composed, at least in part,of a metal alloy. In one embodiment, the metal alloy is composed ofnickel and titanium. In one embodiment, the metal alloy is nitinol.

A locking member 62 is formed at the second end 60 of the guide element52. The locking member 62 has an unlocking configuration and a lockingconfiguration. The locking member 62 is in the unlocking configurationwhen the guide element 52 is in the first position, i.e., fullycontained within the localization needle 54 (see FIG. 13B). The lockingmember 62 is in the locking configuration when the guide element 52 isin the second position, i.e., then the locking member 62 is outside ofthe localization needle 54 (see FIG. 13C). In the illustratedembodiment, the locking wire 62 is formed of multiple wires 64, e.g.,two, which are predisposed toward the locking configuration. When theguide element 52 is slid back into the localization needle 54, the innerchannel 56 of the localization needle 54 constrains and confines thewires 64 in the unlocking configuration. Once the guide element 52 isslid towards and into the second position, the wires 64 are freed fromthe constraints on the localization needle 54 and allowed to move towardand into the locking configuration.

In one aspect of the present invention, the locking configuration isdefined by a predefined shape of the wires 64. In one embodiment, thepredefined shape is a hook shape.

In one embodiment, wires (not shown) may be wrapped around the wires 64to provide rigidity to allow the guide element 52 to be moved within thelocalization needle 54. The number of wires 64, as well as the diameterof the wires 64 (and wires used to provide rigidity) is optimized toprovide maximize holding and as a function of the type of targetedtissue, e.g., hard or soft tissue.

With reference to FIGS. 14 and 15, in another embodiment of the presentinvention, the locking member 62 may include a twisted pair of wires 66.The guide element 52 is shown in the first position in FIG. 14 with thetwisted pair of wires 66 in the unlocking configuration. The guideelement 52 is shown in the second position in FIG. 15 with the twistedpair of wires 66 in the locking configuration.

With reference to FIGS. 16A, 16B, 16C, and 16D, in another embodiment ofthe present invention, the locking member 62 is formed from braided wireor cable 68. As shown, in one embodiment, the distal ends of the cablesmay be straightened and then formed into a predetermined shape, such asa hook shape. The number of wires or cables may vary, e.g., the braidedwire or cable may include 4, 7 or any number of individual wires orcables. The guide element 52 is shown in the first position in FIG. 16Cwith the braided cable 68 in the unlocking configuration. The guideelement 52 is shown in the second position in FIG. 16D with the braidedcable 68 in the locking configuration.

With reference to FIGS. 17 and 18, in another embodiment, the guideelement 52 may include a pushrod 70 and at least two flexible fingers72A, 72B. In one embodiment, the pushrod 70 and flexible fingers 72A,72B are unitarily formed (FIG. 17). In another embodiment, the flexiblefingers 72A, 72B are affixed to the pushrod 70 (FIG. 18).

In one aspect, the flexible fingers 72A, 72B may be predisposed towardsthe locking configuration through a heat treat process.

Returning to FIGS. 7 and 9, in one embodiment of the present invention,the drive assembly 40 may include a variable speed circuit 74electrically coupled to the motor assembly 42, 44. A forward/reverseswitch 76 is electrically coupled to the variable speed circuit 74. Aspeed control trigger 78 is electrically coupled to the variable speedcircuit 74. The forward/reverse switch 76 controls the direction of theDC motor 42, and thus, the direction of movement (forward/reverse) ofthe cannula 20 along the axis 24.

The variable speed circuit 74 controls the speed and rotation of thecannula 20 as a function of the forward/reverse switch 76 and actuationof the speed control trigger 78. In one aspect, the variable speedcircuit 74 has a predetermined speed range, for example 0-100revolutions per minute.

The DC motor and transmission 42 is powered by a rechargeable battery46, which may be charged via an external power source (not shown)through recharging port 48. In one embodiment, the rechargeable battery46 is a lithium ion battery.

The DC motor and transmission 42 is used to provide low speed and hightorque to the drivetrain 44. A drive gear 50 is directly coupled betweenthe motor 42 and the drivetrain 44.

With specific reference to FIGS. 7, 8, and 9, the drivetrain 44 mayinclude a spline gear 80, a spline gear support 82, a lead screw 84, ashaft 86, and a ring gear transmission 88. The spline gear 80 iscontained with the housing 14 and is supported by the spline gearsupport 82. The drive gear 50 engages the spline gear 82 to transferpower to the drivetrain 44, and thus, the coring cannula 20.

The speed of the DC motor 42 is controlled by user actuation of thespeed control trigger 78. The variable speed circuit 74 enables variablespeed ramp up and slow down. In one embodiment, a speed range ofapproximately 0-100 rpm at the cannula may be provided.

The drivetrain 44 is contained within the housing 14, which is removablecoupled to the handle 16. When the device 10 is assembled, the splinegear 80 engages the drive gear 50 within the handle 16. Powertransferred through the drive gear 50 causes rotation of the spline gear80. The spline gear 80 is attached to the spline gear support 82. Thespline gear support 82 is keyed to the shaft 86. The spline gear supportkey 82 provides rotation to the shaft 86 while allowing it to moveaxially (along axis 24). The lead screw 84, which is fixed to thehousing 14, is engaged with threads at the proximal end of the shaft 86.The coring cannula 20 is attached to the shaft 86. As the shaft 86 isrotated, the threaded engagement with the lead screw 84 creates axialmovement of the coring cannula 20.

As the cannula 20 rotates, it continues to move forward for a distancedetermined by the thread length on the lead screw 84. As the shaft 86reaches the end of the threads, it will continue to rotate, but will nolonger move forward. The timing is designed such that when the shaft 86reaches the end of the threaded section of the lead screw 84, thetransmission lockout (lock out button 90) engages. With the lock outbutton 90 engaged, the ring gear assembly 88 is activated and begins toadvance a drive dog 92 forward along the drive screw 50.

The drive dog 92 is coupled to a severing mechanism 94 which is used tosever the tissue contained within the coring cannula 20, which isdescribed more fully below.

The general process of utilization of the device will now be described.First, the localization needle 54 is advanced into the breast underultrasound guidance. In one aspect of the present invention, this isperformed manually. For instance, with the handheld device 10, the usermanually inserts the needle 54 by positioning and manually moving thedevice 10. When the needle 54 reaches the target area, the tissue anchoror locking member 62 is advanced to secure the tissue prior toadvancement of the device 10. Next, the localization needle 54 isreleased allowing the device 10 to move independently of the needle 54.The device 10 is now advanced into the breast, with the stylet blades 32separating the tissue up to the target area. When the device 10 hasreached the target area, the coring cannula 20 is advanced. The cannula20 is advanced by depressing the speed control trigger 78 on the handle16, with the forward/reverse switch 76 in a forward position. When thecannula 20 reaches its full core length, the severing mechanism 94 isactuated, separating the tissue core from surrounding tissue. In oneembodiment, the severing mechanism 94 may include a flexible blade (seebelow) will automatically advance from the distal end of the coringcannula 20. After the core of tissue has been cut free, the device 10 isremoved from the breast. With the device out of the breast, theforward/reverse switch 76 is placed in a reverse position and theflexible blade is retracted using the speed control trigger 78 allowingthe tissue sample to be retrieved from the coring cannula.

As stated above, in one aspect of the present invention, an integratedneedle assembly 18, as shown in FIG. 1 and demonstrated in FIGS. 2A, 2B,2C, and 2D, may be provided. With the integrated needle assembly 18, theneedle assembly 18 and the coring cannula are integrated into a singleunit 18, 20 (see FIG. 2A). With the integrated needle assembly 18, theneedle assembly 18 is inserted within the central passage 34 of thestylet housing 38 when the localization needle 54 is inserted into thebreast (FIG. 2B). Once the localization needle 54 reaches the targettissue, a locking member actuation button 96, located on the top of thehousing 14 is slid forward. The actuation button 96 is linked to thelocking member 62 resulting in the locking member 62 being slid out ofthe localization needle 54 securing the target tissue.

Once the target tissue is secured, the localization needle 54 andlocking member 82 are released from the housing 14 by actuation of oneof the localization needle release button(s) 98 located thereon. Thisallows the device 10 to be slid up localization needle 54 (the styletblades 32 separating the tissue allowing the stylet 28 and coringcannula 20 to pass. Once the coring cannula 20 is adjacent the targettissue, the process proceeds as above.

Then, the device 10 would be fed down the guide rod 104 and the processwould proceed as above (see FIG. 5A).

With respect FIG. 5B, the central passage 34 is formed by the stylettube 36. The stylet tube 36 includes an opening 106 which allows theneedle assembly 18, 18B′ to pass into the central passage 34. The stylettube 36 also may include a guide portion 108 which extends past theopening 106 to assist in the placement of the guide rod into the centralpassage 34.

In another aspect of the present invention, an independent needleassembly 18′ may be provided (see FIGS. 3, 4A, 4B, 5A, 5B). Theindependent needle assembly 18′ is separate from the coring cannula 20.The independent needle assembly 18′ includes a localization needle 54′,an independent needle handle 100, and a plunger 102. The localizationneedle 54′ is inserted into the breast tissue using the handle 100. Oncethe target tissue is reached, the plunger 102 is pushed forward. Thelocking member 62 is pushed forward by the plunger 102, pushing thewires 64 into the target tissue, thereby securing the target tissue. Thelocalization needle 54′ (and handle 100), may thereafter be removed,leaving the locking member 62 within the breast with a guide rod 104extending out of the breast (see FIG. 4B).

The localization needle 54′ has a first end 54A′ and a second end 54′.The localization needle includes an internal channel or bore 56. Thehandle 100 has first and second ends 100A, 100B and an internal bore268. The first end 54A of the needle 54′ is fixed to the second end ofthe handle 100B. The internal bore 56 of the needle 54′ and the internalbore 268 of the handle 100 form an assembly bore 270 therethrough. Inthe illustrated embodiment, the guide element 52 has a guide rod 104 anda locking member 62. The guide element 104 has first and second ends 58,60 and is removably contained within the assembly bore 270. The lockingmember 62 is fixed to the second end 60 of the guide rod 104. Theplunger 102 includes a pushrod 102B and an actuation element 102Acoupled to the pushrod 102B. The plunger 102A is movable from a firststate (FIG. 4A) to a second state (FIG. 4B) One end of the pushrod 102Bacts on the first end 58 of the guide rod 104, forcing the lockingmember 62 out of the needle 18′ as the pushrod 102 is moved from thefirst state to the second state.

With reference to FIGS. 19A-19D, in one embodiment one of the wires 64′from the locking member 62 is detachable from the pushrod 70. It shouldbe noted that although FIGS. 19A-19D illustrated this feature withrespect to the independent needle assembly 18, the detachable wire 64′concept may also be used with the integrated needle assembly 18′.

As shown in FIG. 19A, the locking member 62 is contained within thelocalization needle 54 when the localization needle is initiallyinserted into the breast tissue. When the localization needle 54 reachesthe target tissue, the locking member 62 is deployed as discussed above(FIG. 19B) to secure the target tissue. Then the cannula 20 is advancedover the target tissue and severed using the severing mechanism 94 (seeabove). Once the device 10 has been removed from the breast, thelocalization needle 18′ may be used to push the severed tissue from thecannula 20. The tissue anchors or wires 64 may then be retracted. Thethird hook 64′ may either not be attached to the pushrod 70 or may bedetachable therefore. The third hook or wire 64′ remains attached orsecured to the tissue to provide an orientation marker for the sampleduring pathology (see FIG. 19D).

In another aspect of the present invention, the guide rod 104 mayinclude scale markings 110 to provide an indication to the user thedepth of the anchor/guide element 52 within the breast, as shown inFIGS. 13A and 19B.

In another aspect of the present invention, the biopsy device 12includes a flexible transection blade 112. The flexible transectionblade 112 is a flat metal blade with one end sharpened is formatted tothe required radius (see below). The blade thickness and materialproperties as such that the formed flexible transection blade 112 can beflattened out will “spring” back to its formed shape. The blade 112 willbe held in a flat position along the side of the coring cannula.

The coring cannula 20 will use an angled or non-continuous cutting ring(see below) at the completion of the coring process. As shown in FIGS.20A and 20B, the coring cannula 20 is movable along the axis 24 from aninitial cannula location 118 (shown in dotted lines) to a final cannulalocation 120 in response to rotation of the coring cannula 20 about theaxis 24 in a first direction.

In one embodiment, once the coring cannula 20 reaches the final cannulalocation 120, it will continue to rotate but will not advance axiallyforward. A mechanism 122 will be engaged to drive the flexibletransection blade 112 forward. The flexible transection blade 112 exitsthe coring cannula 20 at a point slightly distal to the cutting edge ofthe coring cannula 20 (see FIGS. 21A and 21B). As the flexible blade 112is driven out of the cannula 20, it will begin to return to itspre-formed curvature. Since this advancement is taking place while thecoring cannula 20 is rotating, the result will be a curved, complete cutthrough the tissue. The path of the blade 112 is designed to intersectwith the distal end of the cutting path from the coring cannula 20,resulting in complete transection and release of the tissue specimen.

With reference to FIGS. 23A, 23B, and 23C, in one embodiment theflexible transection blade 112 consists of a thin strip 124 of springsteel or nitinol. The flexible transection blade 112 has a first end 126and a second or distal end 128. The flexible transection blade 112 iscoupled to the coring cannula 20 at the first end 126. The distal end128 of the flexible transection blade 112 is cut to an optimized angleand sharpened to a cutting edge 114 (see FIG. 23C). A hole mount 130 maybe provided for mounting the blade 112 to the drive assembly 40.

In one embodiment as shown in FIGS. 8 and 9, the flexible transectionblade 112 is stored in a channel 116 built into the coring cannula 20.The flexible transection blade 112 is held flat in this stored position.At the completion of the coring process, the coring cannula 20 willcease axial advancement, but will continue to rotate. During thisrotation the flexible blade 112 is driven forward, advancing past thecoring cannula 20. As the flexible blade 112 advances, it will assumeits pre-formed, curved position. Rotation causes the flexible blade 112to create a semi-circular cut in the tissue. When the flexibletransection blade 112 advances past the center of rotation, a completecut results, releasing the tissue core. The curved blade 112 holds thetissue core inside the cannula 20 until removed from the breast.

The flexible transection blade 112 has a first blade position and asecond blade position. The flexible transection blade 112 is in thefirst blade position while the coring cannula 20 is between the initialand final cannula locations 118, 120. As shown in FIG. 20A, in oneembodiment, when the flexible transection blade 112 is in the firstblade position it is contained within the coring cannula 20, and thus,not visible. Rotation of the coring cannula 20 in the first directionwhile the coring cannula 20 is at the final cannula location 120 rotatesthe flexible transection blade 112 about the axis 24, moving theflexible transection blade 112 from the first blade position to thesecond blade position (shown in FIG. 22B).

Testing has revealed a few key elements of the invention. First, themost efficient cutting of tissue is accomplished by creating relativemotion between cutting surface, i.e., the cutting edge 114, and tissue.Second, the relationship between the cutting edge 114 and the rate ofadvancement of the length and angle of the cutting edge 114 must resultin a cutting surface that is greater in length than the linearadvancement per revolution. Further, the rate of advancement perrevolution should be optimized to minimize cutting forces. This approachwill ensure that a thin, flexible blade 112 will follow the desiredcutting path.

With particular reference to FIGS. 24, 25A, and 25B, in one embodimentthe mechanism 122 may include a friction wheel transmission 132. Thefriction wheel transmission 132 includes friction wheel 134 which isforce fit over the shaft 26. The shaft 26 is directly coupled to thecannula 20 through a drive ring 20 which is fixed to the housing 14. Adrive screw 136 is fixed to the friction wheel 134, which is coupled tothe flexible transection blade 112. As the shaft 26 is advanced by thedrive assembly 40, the friction wheel 134, and thus the flexibletransection blade 116 is also advanced. The friction wheel 134 is forcefit over the shaft 26 such that the transmission force may becontrolled. The relationship between the friction wheel 134 and thedrive ring 136 and/or the relationship between the friction wheel 134and the shaft 26 can be adjusted so that if the force encountered by theflexible transection blade 112 increases to a certain point, thefriction wheel 134 will slip on the shaft 26 preventing furtheradvancement of the blade 112. The blade 112 will continue to rotateuntil the sample tissue has been cut and the forces reduced. Bladeadvancement will then automatically resume.

With particular reference to FIGS. 26, 27, and 28, in another embodimentthe mechanism 122 may include a gear drive transmission 140. The geardrive transmission 140 provides continuous drive with maximum powertransfer. In one aspect of the present invention, the gears within thegear drive transmission 140 remain meshed but do not rotate during axialadvancement of the coring cannula 20. When advancement of the coringcannula 20 is complete, the gear drive transmission 140 automaticallyengages and begins to drive the flexible transection blade 112.

The gear drive transmission 140 may include a gear housing 146, a ringgear 150, and a drive gear 152. A plunger 144 is slidably coupled to thegear housing 146 and is spring biased in an outward direction. While thecoring cannula 20 is between the initial cannula location 118 and thefinal cannula location 120, plunger 144 is pressed inwardly by the innerwall of the housing 20 such that one end is inserted a receiving slot148 on the shaft 26. Thus, the gear housing 146 is locked relative tothe shaft 26. The shaft gear housing 146 thereby rotates with the shaft26, and there is no relative motion between the gears 140, 152. When thegear housing 146 reaches a release slot 154 in the housing 14, thespring biased plunger 144 slides into the release slot 154, therebyreleasing the shaft 26, the ring gear 150 is fixed relative to thehousing 14 and the drive gear 152 rotates with the shaft 26, therebydriving the flexible transection blade 112 forward.

With particular reference to FIG. 29, in still another embodiment a leadscrew 156 is used to enable the shaft 26 to advance and rotate, stopadvancing but continue rotating and then retract to its originalposition. The shaft 24 includes an opening 158 leading to a shaftthreaded section 160. The lead screw 156 is rotatably fixed to thehousing 14 and includes a first end portion 162, a second end portion164, and a lead screw threaded section 166, which meshes with the shaftthreaded section 160.

The shaft 26 is driven forward (to the right in FIG. 29) until the backedge of shaft 174 reaches the front edge of lead screw threads 178. Atthis position, the shaft 26 will continue to rotate but no longeradvances. The shaft threaded portion 160 is supported by shoulder 180. Afirst spring 168 makes contact with surface 172 exerting a slightbackward force on the shaft 26.

When the drive assembly 40 is reversed, the force exerted on surface 172by the first spring 168 urges re-start of threads between the shaft 26and the lead screw 156. The shaft 26 will then move backward until thecontact surface 176 clears the surface 172. A second spring 170 nowprovides force to urge restart in the forward direction.

This configuration may also be adopted to drive the flexible transectionblade 112.

With particular reference to FIG. 30 in still another embodiment, adrive screw 184 may be used to drive motion of the flexible transectionblade 112. A drive gear 182 is fixed to the drive screw 184 which isthreadably coupled to the drive dog 186. During forward motion of thecoring cannula 20, the drive dog 186 is allowed to slip relative to thedrive screw 184. During activation of the flexible transection blade112, the drive gear 182, and thus, the drive screw 184 rotate. The drivedog 186 has an internal threaded bore (not shown) which is mated withthe drive screw 184. As the drive screw 184 rotates, the drive dog 186advances (or retracts) along the screw 184, thereby advancing theflexible transection blade 112.

With particular reference to FIG. 31, in a further embodiment, amodification is shown. In the illustrated embodiment, the drive dog 186′is fixed to an end of the drive screw 184′. The drive gear 182′ has ininternal threaded bore (not shown) which is mated with the drive screw184′. As the drive gear 182′ rotates, the drive screw 184′ and the drivedog 186′ advances or retracts.

As discussed more fully below, the cutting edge 114 of the cuttingcannula 20 may be formed by a cannula insert 188 and may have differentconfigurations.

With particular reference to FIGS. 32A and 32B, the cannula insert 188forms a circular coring blade 190. As shown the flexible transectionblade 112 advances past the circular coring blade 190. The flexibleblade 112 transects tissue distal to the front edge of cutting ring 190.

With particular reference to FIGS. 33A and 33B, in another embodimentthe cannula insert 188 forms a partial cutting ring 192. The partialcutting ring 192 forms a partial cutting face 194 with an angled edge196. As the coring cannula 20 rotates, the angled edge 196 cuts throughthe tissue. As shown, with the partial cutting ring 192, the flexibletransection blade 112 does not extend past the furthermost edge of thepartial cutting rung 192. Thus, the tissue sample is confined within thecutting ring 192.

With particular reference to FIGS. 34A and 34B, in still anotherembodiment, the cutting edge 114 of the flexible transection blade 112is used to core the sample tissue (FIG. 34A). The flexible transectionblade 112 is then advanced to transect tissue (FIG. 34B).

With particular reference to FIG. 35, a prior art cutting ring 200 isshown. The prior art cutting ring 200 is nestled within a bore 202 ofthe distal end of the cutting cannula 20. As shown, the coring cannula20 has an inner diameter of d₁ and the cutting ring 200 has an innerdiameter of d₂. In the prior art device shown in FIG. 35, d₁ issubstantially equally to d₂. The outer surface of the coring cannula 205has a ramping surface 206 from the outer dimension of the coring cannula205 to the distal end of the coring cannula 205. As shown, the outerdiameter of the coring cannula d₄ is greater than the outer dimension,d₃, of the prior art cutting ring 200.

In the prior art cutting ring 200 of FIG. 35, the mechanism fortransecting the tissue sample is a garrote wire 204 which transversesthe outer wall of the coring cannula 20. At a location near the distalend of the coring cannula 205 the garrote wire 204 forms a right angleand encircles the inner diameter of the coring cannula 20. As shown,this occurs at a substantial distance, d₅, from the distal end of thecutting ring 200. This arrangement presents two problems. First, the 90degree bend in the garrote wire 204 significantly increases the forcerequired to pull the garrote wire and transect the tissue. Second, thelarge distance, d₅, between the garrote wire 204 and the cutting edge ofthe cutting ring 200, results in a core of tissue, or tissue plug, whichis cored by the coring cannula 205, but not transected by the garrotewire. This cored tissue thus remains in the breast.

With particular reference to FIGS. 36A and 36B, in one embodiment apartial cutting ring 208 may be provided. The illustrated partialcutting ring 208 may include a face cutting surface 208A, which has acutting edge perpendicular to the axis 24, and a side cutting surface208B. The use of the side cutting surface 208B introduces side cutting.Side cutting is less likely to result in unwanted pushing or movement oftissue. Additionally, the blade angle allows the garrote wire 210 to beinstalled outside of the coring blade and then clear of the cutting ringwhen retracting. This also limits the tissue plug problem identifiedabove. Furthermore, the angle in the garrote wire 210 may be increased(as shown), reducing the required transection forces (see FIGS. 37A,37B, 37C).

With reference to FIGS. 38A, 38B, and 39 in an other aspect of thepresent invention, the coring cannula 20 may include an external cuttingring 198. The external cutting ring 198 has an interior bore 212 withinan interior diameter, d₂. The coring cannula 20 has a reduced diameterportion 214 at its distal end. As shown, the external cutting ring 198is fitted over the reduced diameter portion of the coring cannula 214.As shown, the outer diameter (d₄) of the coring cannula 20 issubstantially equal to the outer diameter of the external cutting ring,d₃.

As shown, the transecting mechanism 122 may include a garrote wire 210.

With specific reference to FIGS. 38A and 38B, in one embodiment thegarrote wire 210 is removably coupled to the coring cannula 20 by one ormore bent tabs 216 formed integrally with the coring cannula 20. The oneor more bent tabs 216 may be integrally formed with the coring cannula20. The mechanism 122 is located at the distal end of the coring cannula20. The distal end of the coring cannula 20 is within a minimal distanceof the distal end of the external cutting ring 198. This minimizes thetissue plug problem discussed above. In one embodiment, the minimaldistance is <0.25 inches.

With specific reference to FIG. 39, the distal end of the externalcutting ring 198 is spaced from the distal end of the coring cannula 20.In the illustrated embodiment, the mechanism 122 is located at thedistal end of the external cutting ring 198. The mechanism 122 is withinthe minimal distance of the distal end of the external cutting ring 198.The garrote wire may be removably held in place by one or more tabs 218which may be formed integrally with the cutting ring 198.

With particular reference to FIG. 41, in one aspect of the presentinvention, the coring cannula 20 may be provided with a cutting ring inwhich the inner diameter of the coring cannula 20 has an inner diameterwhich is smaller than the inner diameter of the cutting ring. Tissue isflexible, malleable and compressible. With the inner diameter of thecoring cannula 20 being smaller than the inner diameter of the cuttingring, the tissue sample is compressed as it enters the coring cannula 20(behind the cutting ring). Compression of the tissue sample results inbetter retention of the tissue sample in the cannula 20. Additionally,with the reduced inner diameter of the cannula 20, the outer diameter ofthe cannula 20 may also be reduced, until it is the equal to or nearlyequal to the outer diameter of the cutting ring. This results in (1) asmaller entry incision and (2) reduction of the required coring cuttingforce.

With particular reference to FIG. 40, a prior art cannula 222 is shown.The prior art cannula 222 has a cutting ring 224. The prior art coringcannula 222 has an inner diameter (d₁) which is equal to the innerdiameter (d₂) of the cutting ring 224. Additionally, the outer diameter(d₄) of the prior art coring cannula 222 is greater than the outerdiameter (d₃) of the cutting ring 224.

With particular reference to FIG. 41, a coring cannula 226 according toan embodiment of the present invention is shown. The coring cannula 226has a distal end 228 and is centered on the axis 24 and is coupled tothe housing 14. The coring cannula 226 having an inner surface 230forming a cannula bore 232. The cannula bore 232 has an inner diameter(d₁) and is rotatable about the axis. A cutting ring 234 has an innersurface 236 which forms a cutting ring bore 238 and is located at thedistal end of the coring cannula 226. The cutting ring bore 238 has aninterior diameter (d₂). A tapered wall 240 is coupled between the coringcannula 226 and the cutting ring 234. The tapered wall 240 provides aramped surface between the inner surface 236 of the cutting ring 234 andthe inner surface 236 of the coring cannula 226.

As discussed, the inner diameter, d₁, of the cannula bore 232 is lessthan the inner diameter, d₂, of the cutting ring 234. Furthermore, theouter diameter, d₄, of the coring cannula 226 is equal to, or onlyslightly larger than, the outer diameter, d₃, of the cutting ring 234.

In one embodiment, the coring cannula 226 and the cutting ring 234 areunitarily formed. In an other embodiment, the coring cannula 226 and thecutting ring 234 are formed separately. In one embodiment (as describedabove), the coring cannula 226 may have a reduced diameter portionformed at the distal end 228. The cutting ring 234 is an externalcutting ring which is fitted over the reduced diameter portion of thecoring cannula. The distal end of the cutting ring 234 forms a coringcannula cutting edge 238.

With reference to FIGS. 42A, 42B, 43A, 43B, 43C, in another aspect ofthe present invention a collapsible stylet may be provided (see below).With particular reference to FIGS. 42A and 42B, a prior art stylet 242is shown. The prior art stylet 242 is contained within the coringcannula 244. The prior art stylet 242 has a slot 243 for the styletblades 246. The diameter, d₁, of the prior art stylet 242 is fixed, andsmaller than the diameter, d₂, of the cutting edge 248 of the coringcannula 244. Thus, in use, after the stylet 242 has cut into the tissue,the skin may need to be opened further to allow the coring cannula 244to enter the tissue.

With particular reference to FIGS. 43A, 43B, and 43C, a collapsiblestylet 250 according to one embodiment of the present invention isillustrated. The coring cannula 20 has a distal end 252, a longitudinalaxis 24 and is centered on the axis 24 (see above). The collapsiblestylet 250 has a tip 254, which contains at least one blade 256, and acentral passage 258 and is coupled to the coring cannula 20. The tip 254has a recess 260 located near a proximal end 262 thereof. The tip 254 ismovable between an initial configuration (shown in FIGS. 43A and 43B)and a contracted configuration (shown in FIGS. 43C and 43D). When thetip 254 is in the initial configuration, the cutting edge 264 of thecoring cannula 20 is within the recess 260. This allows the coringcannula 20 to enter the incision with the stylet 250, prior to thecoring process, without the need to widen or open the incision anyfurther. The tip 250 remains in the initial configuration as the coringcannula 20 is moved from the initial cannula location towards the finalcannula location. Once the coring cannula 20 reaches the final cannulalocation, the tip may be moved into the contracted configuration (FIG.43C). In the contract configuration, the cutting edge 264 of the coringcannula 20 is exposed when the tip 254 is in the contractedconfiguration.

In the illustrated embodiment, the tip 254 has a first half portion 254Aand a second half portion 254B. As shown in the illustrated embodiment,the first and second half portions 254A, 254B have a semi-circularcross-section (see FIGS. 43B and 43C) and an inner surface 268A, 268B.The inner surface 266A of the first portion 254A faces the inner surface266B of the second portion 254B. The first and second half portions254A, 254B have a first part 268A, 268B and a second part 270A, 270B.The second parts 270A, 270B are sloped and curved forming an entrysegment 272. The first and second parts 268A, 268B form a linear segment274. The linear segment 274 has an associated first diameter, (d₁), whenthe tip is in the initial configuration (FIG. 43B). The first diameterassociated with the linear segment 274 is greater than or equal to adiameter associated with the cutting edge 248 of the coring cannula 20.Thus, the cutting edge 248 can sit within the recess 260 prior to thecoring process (see above).

As shown in FIG. 43C, when the tip 254 is in the contractedconfiguration the linear segment 274 has a second diameter, (d₂). Thesecond diameter is less than diameter associated with the cutting edge248 of the coring cannula 20. This allows the coring cannula 20 to berotated and moved forward (over the stylet) to perform the coringprocess.

In one embodiment, the first and second half portions 254A, 254B arebiased towards the initial configuration. In the illustrated embodiment,the collapsible stylet 250 includes a collet tube 251 and a colletcloser 253. As shown, the tube 251 includes a ramping portion 251A and adistal end 251B. The distal end 251B is fitted between the first andsecond half portions 254A, 254B and bias the first and second halfportions 254A, 254B into the initial configuration. A collet closer 253is provided which is movable between a first position (shown in FIG.43A) and a second position (shown in FIG. 43C). The collet closer 253acts on the ramping portion 251A of the collet tube 251 to compress thedistal end 251B. This allows the, the first and second half portions254A, 254B of the collapsible stylet 250 to collapse to the contractposition. The collet closer 253 may be movable from the first positionto the second position by the user through actuation of a buttonprovided on the housing 14 (not shown).

With specific reference to FIGS. 44 and 45, in another aspect of thepresent invention, an independent stylet mechanism 276 is provided. Withparticular reference to FIG. 44, a prior art stylet 278 is shown. Theprior art stylet 278 includes integral cutting blades 280. Since theintegral cutting blades 280 are fixed relating to the stylet tip, thedistance between the blades 280 and the stylet 278 is fixed at a minimaldistance. This increases the chances of inadvertent movement orcompression of the tissue, i.e., “snowplowing”.

With specific reference to FIG. 45, the independent/retractable styletmechanism 276 includes a tube 282 and at least one stylet blade 284affixed to the tube 282. A stylet 286 includes a stylet tip 288 with acentral passage 290. The tube 282 is slidably disposed within thecentral passage 290 of the stylet 286.

In the illustrated embodiment, the stylet mechanism 276 includes firstand second blades 284A, 284B.

In one aspect, the tube 282 may include an internal bore 292 forreceiving the guide element 52 (see above).

The independent/retractable stylet mechanism 276 is adjustablewithin/along the central passage 290 of the stylet 286. Thus, the usercan adjust the distance between the blades 284 and the stylet tip 288 toreduce the chance of snowplowing occurring.

With reference to FIGS. 46A-46D and 47A-47C, in another aspect of thepresent invention, a localization needle with an integral locking member294 is provided. In one embodiment, the localization needle 294 includesa needle portion 296 and a locking member 304. The needle portion 296having a proximal end 298, a distal end 300 and a channel 302 formedtherein.

The locking member 304 is formed integrally with the needle portion 296.As shown, the locking member 304 may be formed at the distal end 300 ofthe needle portion 296 and has an unlocking configuration (shown in FIG.46A) and a locking configuration (shown in FIG. 46B).

In the illustrated embodiment, in the unlocking configuration, thelocalization needle 294 is straight, i.e., without bends or kinks. Inthe locking configuration, bends, or barbs, as shown in FIG. 46B havebeen introduced into the localization needle 294. These bends, barbs,are introduced into the localization needle 294 after the localizationneedle 294 has been inserted into the breast, thereby locking thelocalization needle 294 relative to the target tissue (see above).

In one embodiment, the localization needle 294 includes an actuationdevice 306. The actuation device 306 is coupled to the distal end 300and is used to apply a force thereto (see FIG. 46B). The force acts tobring the distal end 300 closer to the proximal end 298. With theproximal end 298 fixed to, for example, the housing 14 of the biopsydevice 10, the localization needle 294 collapses at the locking member304 creating the barbs, or extensions, as shown, thereby controllablymoving the locking member from the unlocking configuration to thelocking configuration.

In one aspect of the present invention, the actuation device 306includes a member 308 coupled to an inner surface of the distal end 300of the needle portion 296.

With particular reference to FIG. 46C, in one embodiment the member 308may include a wire 310 fixed to the inner diameter of the localizationneedle 294. The wire 310 may be attached to a lever (not shown) on thehousing, or some other suitable mechanism, which pulls the wire 310 backtoward the proximal end 298.

In another embodiment, the member 308 is a threaded rod 312 which isreceived by a threaded receiving member 314 which is coupled to theinner surface of the distal end 300 of the needle portion 296. Thisarrangement allows the localization needle 294 to be moved back into theunlocking configuration if the placement needs to be corrected.

In another aspect of the present invention, the locking member 304 isformed by at least one pair of opposed slots 316 within the needleportion 296. In one embodiment, the slots 316 may be laser cut from theneedle portion 296. As shown in FIGS. 46A-46D, in one embodiment, theslots 316 may have a general rectangular shape with rounded ends. Theslots 316 may include one or may directional cutouts 317 which assist informing the extensions or barbs. The directional cutouts 317 may betriangular shaped.

In another aspect of the present invention the slots 316 may have ageneral diamond shape, as shown in FIGS. 47A-47C.

With particular reference to FIGS. 48A, 48B, and 49, in another aspectof the present invention, one or more rotating circular blades 318,318A, 318B may be used. The use of the rotating circular blades 318,318A, 318B improves the efficiency of the stylet and reduces the risk ofcompression and/or tearing of the tissue as the stylet in pushed intothe breast.

The rotating circular blade(s) 318, 318A, 318B may be powered (seebelow) or may rotating freely. The rotation of the blade (s) 318, 318A,318B whether from an external source or as a result of friction betweenthe blade 318, 318A, 318B and the tissue, creates relative motiontherebetween.

With particular reference to FIG. 48A, in one embodiment a stylet 320 isprovided with a single rotating circular blade 318. The stylet 320 iscoupled to a coring cannula 322. The coring cannula 322 has alongitudinal axis 324 and is centered on the axis 324. The stylet 320 iscoupled to the coring cannula 322. The stylet 320 includes a stylet tube326. The rotating circular blade 318 is rotatably coupled to a distalend 328 of the stylet tube 326.

With particular reference to FIG. 48B, in another embodiment, therotating circular blade 318 is not mechanically driven, but is allowedto freely rotate. As the device 10 is advanced into the tissue, forceexerted by the tissue will tend to rotate the circular blade 318,eliminating the tendency to push/tear tissue and improving cuttingefficiency.

In both embodiments, the singular rotating circular blade 318 is mountedon its center point 334. As shown, the center point 334 is centered overthe stylet tube 326.

The rotating circular blade 318 defines a first plane which is parallelto the axis 324. The axis defines a second plane. The first and secondplanes intersect at a right angle. The center point 334 of the rotatingcircular blade 318 is located on both the first and second planes.

A blade drive mechanism 330 is coupled to the rotating circular blade318 for controllably rotating the circular blade 318. In one embodiment,the blade drive mechanism 330 may include a motor (not shown) and drivecable 332. Alternatively, the blade drive mechanism 330 may include arod and gearing system (not shown).

With particular reference to FIG. 49, the stylet 320 may include a pairof offset blades 318A, 318B. The second blade 318B defines a third planewhich is parallel to the first plane. As shown in FIG. 39, the center334A, 334B of the blades 318A, 318B are offset a predetermined distance.The first and second blades 318A, 318B may be mechanically driven or maybe allowed to rotate freely.

Returning to FIGS. 2A-2D, 5A and 5B, in another aspect of the presentinvention the biopsy device 10 includes at least one retractable styletblade 336. The at least one retractable stylet blade 336 is part of astylet blade mechanism 338. The stylet blade mechanism 338 may includefirst and second retractable blades 336A, 336B, as shown.

The stylet blade mechanism 338 is coupled to the coring cannula 20 viathe stylet tip 30. In one embodiment, the stylet blade mechanism 338includes the stylet tube 36. The at least one retractable stylet blade336 is fixed to the stylet tube 36. The stylet tube 36 is slidablydisposed within the stylet housing 38. The central passage 34 is formedby the stylet tube 36.

The stylet blade mechanism 338 is movable between a cutting position anda retracted position. In the cutting position, the at least one styletblade is located a distance in front of the stylet tip 30 (as shown). Inthe retracted position, the at least one stylet blade 336 is locatedwithin the stylet tip 30.

In one embodiment, the stylet blade mechanism 338 may be manually movedfrom the retracted position to the cutting position. In one embodiment,the stylet blade mechanism 338 is spring biased towards the cuttingposition.

As discussed above, the biopsy device 10 may further comprise a guideportion 108 formed at the end of the stylet tube 30. The guide portion108 extends past an opening of the stylet tube 30. The guide portion 108having an interior curved surface 340. The interior curved surface 340assists in guiding the end of the guide element 52 into the centralpassageway 108.

It should be noted that the stylet blade mechanism 338 and theretractable stylet blades 336 may be used with either integratedlocalization needle or the independent needle (see above). With respectto FIGS. 5A and 5B, the stylet blade mechanism 338 is used with theindependent needle handle assembly 18′. As discussed above, theindependent needle handle assembly 18′ is inserted into the breast, theguide element 52 is extended outside of the needle 54 and the lockingmember 62 is affixed to the target tissue. Once the locking member 62 islocked into the target tissue, the guide element 52 is removed from theneedle 54. The guide element 52 is then inserted into central passageway108.

With the guide element 52 within the central passageway 108 and thestylet blade mechanism 338 in the cutting position, the biopsy device 10is slid up the guide element 52, the stylet blades 336 cutting thetissue and allowing the device 10 to reach the target tissue. Once thetarget tissue is reached, the stylet blade mechanism 338 can beretracted such that the blade(s) 336 are contained within the tip 30.The coring cannula 20 can then be advanced over the target tissue.

With reference to FIGS. 50A, 50B, 50C, 50D, 51A and 51B, in stillanother aspect of the present invention, a garrote wire 210 is used totransect the tissue sample.

The prior art devices, which employ a garrote wire, use a linear pull“trigger” system to activate the garrote wire. A limitation of thedesign is the travel required to fully pull the garrote wire. Thislimitation becomes an issue for larger cannula sizes. As the cannuladiameter increases, the length of garrote wire required to transecttissue increases resulting in an increase in required travel. The travellength is limited by the overall length of the device. Continuing toincrease the device length is not a viable option.

As discussed below, the breast biopsy device 10 may include a triggermechanism 342 which includes a trigger 344 (shown diagrammatically inFIGS. 50A-51B). The trigger 344 is generally pulled backward to pullgarrote wire 210 backward, thereby transecting the tissue sample withinthe coring cannula 20.

As shown in FIG. 50A, the breast biopsy device 10 includes a pair ofrotatable cleats 346 which are coupled to the housing 14 (through atrigger body 350) and are rotatable between a first cleat position(shown in FIG. 50A) and a second cleat position (shown in FIG. 50B). Asshown, in one embodiment, the rotatable cleats 346 include a pluralityof teeth 348 which grip the garrote wire 210. The cleats 346 are coupledto the trigger mechanism 342 and when the trigger mechanism 342 isactuated, i.e., pulled backward relative to the housing 14. Frictioncauses the cleats 346 to rotate, thereby engaging the teeth 348 into thegarrote wire 210. Then, as the trigger mechanism 342 is pulled backward,the cleats 346 move therewith, pulling the garrote wire 210 as well.

With specific reference to FIG. 50A, when the garrote wire 210 is in afirst position, the wire 210 forms a loop 352 which is external to thecoring cannula 20. After the coring cannula 20 is extended and surroundsthe sample tissue, the trigger mechanism 342 is used to completeseparate the sample tissue from the breast.

In one embodiment, a single actuation of the trigger mechanism 342,e.g., a single pull of the trigger 342, moves the garrote wire 210 fromthe first wire position to a second wire position in which the garrotewire 210 is within the coring cannula 20 (and the sample completelyseparated from the breast).

In another embodiment, multiple actuations of the trigger mechanism 342,or multiple pulls of the trigger 344, are required. In the illustratedembodiment, two pulls of the trigger 344 are required. Each pull of thetrigger 344, moving the garrote wire a distance defined by the distancebetween X₁ and X₂.

FIG. 50A shows the garrote wire 210 in an initial position with the loop352 in its largest configuration. FIG. 50B shows the garrote wire 210 inan intermediate location, after the first pull of the trigger 344 (thetrigger 344 and trigger body 350 are shown at full travel).

FIG. 50C shows the garrote wire 210 at the intermediate location, withthe trigger body 350 returned to the initial position. In one aspect,the trigger body 350 is spring biased back to the initial position. Inanother aspect, the trigger body 350 may be manually moved back to theinitial position.

FIG. 50D shows the garrote wire 210 at the final location, fullyactuated and within the coring cannula 20. At this point, the sample iscompletely severed from the breast.

This improvement to the linear pull system will enable the use of largercannula sizes to provide for multiple pulls of the trigger 344 on thegarrote wire 210. Multiple pulls can be accomplished using the breakawaycleat system. The cleat system works as follows: When the trigger 348 ispulled, cleats 346 with separated edges or teeth 348 grip the garrotewire 210, allow the trigger 344 to pull the wire 219 the full length oftravel. At the end of travel, the trigger 344 is pushed forward back tothe start position. When the trigger 344 is moved in this direction, thecleat 346 (cam) disengages the wire so that the trigger 344 slidesforward without affecting the wire 210. As the trigger 344 is pulledback, the cleats 346 re-engage the wire 210, pulling it to furthertransect tissue. This process is repeated until transection iscompleted.

With reference to FIG. 51A in a further embodiment, a second pairrotatable cleats 354 may be fixed directly to the device 10, e.g.,directly to the housing 14. The second pair of rotatable cleats 354 arenot fixed to the trigger body 350. The second pair of cleats 354prevented undesirable forward motion of the garrote wire 210.

With reference to FIG. 51B in an other embodiment, the garrote wire 210may have a number of beads 356 fixed thereto (crimped or welded thereon)to assist in grabbing of the wire by the cleats 346, 354.

As discussed above, the prior art utilizes a linear pull trigger system,in which the trigger is pulled straight back to actuate the garrotewire. The trigger rides in a track and is supported by guide rods tomaintain the desired linear pull. When the trigger is pulled back itengages a support ring attached to the garrote wire. This support ringmoves backward with the trigger, pulling the garrote wire across thecannula, transecting the core of tissue at the distal end. However,there are a significant number of cases which encounter “tough” breasttissue. When tough tissue is encountered, transection force increasessignificantly, at times resulting in incomplete transection. The usercannot provide enough input force to fully actuate the trigger system.Occurrences of this problem increases as cannula diameter increases.

Constriction and transection of breast tissue by the garrote wire canbest be described by separating it into two phases. Phase 1 includes 0%to 70-95% constriction of the tissue by the garrote wire. The 70-95%range is dependent on cannula size and tissue density. The requirementsof Phase 1 are long travel and low/medium input force. The currentlinear pull system works well during Phase 1. Phase 2 covers up to thefinal 30% of tissue constriction and eventual transection. Therequirements of Phase 2 are limited travel with potentially high inputforces required. The linear pull system does not always meet theserequirements.

With reference to FIGS. 52A, 52B, 52C, and 52D, in another aspect of thepresent invention, the garrote wire 210 actuation by a trigger mechanism358. The trigger mechanism 358 is coupled to the housing 14 and thegarrote wire 210 (via support ring 370). In the illustrated embodiment,the trigger mechanism 358 includes a trigger 360 slidably mounted in atrigger channel 362 in the housing 14. In the illustrated embodiment thetrigger channel 362 is formed by a linear support track 368 within thehousing 14. The trigger 360 is movable from a first trigger position(shown in FIGS. 52A and 52B) to an intermediate trigger position (shownin FIG. 52C) within the trigger channel 362.

The garrote wire 210 is coupled directly to the trigger 360. In responseto the trigger 360 being moved from the first trigger position to theintermediate trigger position, the garrote wire is moved from the firstwire position to an intermediate wire position. In the illustratedembodiment, the triggers 360 drops into a cam channel 366 once itreaches the intermediate trigger position.

Once the trigger 360 reaches the intermediate trigger position it canmove no further within the trigger channel 362. The trigger 360 isfurther rotatably movable about a trigger axis 364 from the intermediatetrigger position to a second trigger position (shown dotted lines inFIGS. 52D). In response to movement of the trigger 360 to the secondtrigger position, the garrote wire 210 is moved from the intermediatewire position to the second wire position in response thereto.

The addition of a rotational cam mechanism, i.e., the rotatable trigger360, to the trigger mechanism 358 will address Phase 2. The rotationalcam provides a mechanical advantage to the user allowing greater inputforce with limited travel. The concept described here is a “hybrid”system, using the linear pull system for the first 70-95% wire traveland then switching to the rotational cam system for the final phase oftransection.

In use, the user will pull the trigger 360 along the linear track. At anoptimized position, the trigger 360 will reach the end of the triggerchannel and engage the cam activation system. In this position thetrigger will no longer translate, but will now rotate so that the inputforce is transferred through the cam to the support ring 370.

Any modifications and variations of the present invention are possiblein light of the above teachings. The invention may be practicedotherwise than as specifically described within the scope of theappended claims.

1. A needle assembly, comprising: a localization needle having first andsecond ends and an internal bore; a handle having first and second endsand an internal bore, the first end of the needle fixed to the secondend of the handle, the internal bore of the needle and the internal boreof the handle forming an assembly bore therethrough; a guide elementhaving a guide rod and a locking member, the guide element having firstand second ends and being removably contained within the assembly bore,the locking member being fixed to the second end of the guide rod; and,a plunger, having a pushrod and an actuation element coupled to thepushrod, the plunger being movable from a first state to a second state,one end of the pushrod acting on the first end of the guide rod, forcingthe locking member out of the needle as the pushrod is moved from thefirst state to the second state.
 2. A needle assembly, as set forth inclaim 1, the locking member having an unlocking configuration and alocking configuration, the locking member being in the unlockingconfiguration and contained within the localization needle when theplunger is in the first state, the locking member being in the lockingconfiguration and being outside the localization needle when the plungeris in the second state.
 3. A biopsy device, as set forth in claim 1,wherein the locking member is composed of a section of the guide elementwhich is predisposed to a predefined shape when the second end of theguide element is unconstrained.
 4. A biopsy device, as set forth inclaim 3, wherein the predefined shape is a hook shape.
 5. A biopsydevice, as set forth in claim 4, wherein the locking member is composedof a plurality of wires having the predefined shape, and at least one ofthe wires is detachable from the locking member.
 6. A biopsy device, asset forth in claim 4, wherein the guide element includes a twisted pairof wires.
 7. A biopsy device, as set forth in claim 1, wherein the guideelement is formed from braided wire.
 8. A biopsy device, as set forth inclaim 1, wherein the guide element is composed of a metal alloy ofnickel and titanium.
 9. A biopsy device, as set forth in claim 8,wherein the metal allow is nitinol.
 10. A biopsy device, as set forth inclaim 1, wherein the guide element includes a pushrod and two moreflexible fingers.
 11. A biopsy device, as set forth in claim 10, whereinthe pushrod and flexible fingers are unitarily formed.
 12. A biopsydevice as set forth in claim 10, wherein the fingers are affixed to thepushrod.
 13. A biopsy device, as set forth in claim 10, wherein theflexible fingers are predisposed to the locking configuration through aheat treat process.
 14. A biopsy device, comprising: a housing; a coringcannula coupled to the housing and having a longitudinal axis and ashaft centered on the axis; a stylet having a tip containing at leastone blade and a central passage; a localization needle having a channeland being slidably disposed within the central passage; a motor assemblycoupled to the coring cannula for controllably rotating the cannula; avariable speed circuit electrically coupled to the motor assembly; aforward/reverse switch electrically coupled to the variable speedcircuit for controlling the direction of movement of the cannula; aspeed control trigger electrically coupled to the variable speedcircuit, the variable speed circuit for responsively controlling thespeed and rotation of the cannula as a function of the forward/reverseswitch and actuation of the speed control trigger; and, a needleassembly removably coupled to the housing, the needle assemblyincluding: a localization needle having first and second ends and aninternal bore; a handle having first and second ends and an internalbore, the first end of the needle fixed to the second end of the handle,the internal bore of the needle and the internal bore of the handleforming an assembly bore therethrough; a guide element having a guiderod and a locking member, the guide element having first and second endsand being removably contained within the assembly bore, the lockingmember being fixed to the second end of the guide rod; and, a plunger,having a pushrod and an actuation element coupled to the pushrod, theplunger being movable from a first state to a second state, one end ofthe pushrod acting on the first end of the guide rod, forcing thelocking member out of the needle as the pushrod is moved from the firststate to the second state.
 15. A biopsy device, as set forth in claim14, wherein the locking member is composed of a section of the guideelement which is predisposed to a predefined shape when the second endof the guide element is unconstrained.
 16. A biopsy device, as set forthin claim 15, wherein the predefined shape is a hook shape.
 17. A biopsydevice, as set forth in claim 16, wherein the locking member is composedof a plurality of wires having the predefined shape, and at least one ofthe wires is detachable from the locking member.